Field of the Invention
The present invention relates to a novel Listeria bacteriophage designated ProCC P825. In particular, the present invention relates to the endolysin PlyP825 encoded by the novel phage ProCC P825 and uses of the novel endolysin PlyP825 for controlling Listeria contamination and infection.
Description of Related Art
The gram-positive bacterium Listeria monocytogenes is a bacterial pathogen which is known as the causative organism in several outbreaks of food-borne disease. Listeriosis is a life-threatening infection of humans worldwide which is caused by Listeria monocytogenes and which is characterized by a variety of symptoms and conditions, including diarrhea, abortion and encephalitis. In industrialized countries, high mortality is associated with listeriosis following Listeria monocytogenes food contamination. In humans, the prevalence of listeriosis has risen significantly since the 1980s, resulting in intensified surveillance of Listeria monocytogenes in food industry. This contributed to a decrease of human listeriosis cases in the last two decades (McLauchlin 1987, Oevermann et al. 2008). However, its prevalence has again increased in the last few years (Gillespie et al. 2006, Goulet et al. 2008, Gillespie et al. 2009).
The species Listeria monocytogenes encompasses numerous strains and the genetic diversity amongst them is high (Doumith et al. 2004). Various strains have been implicated in both human and animal disease, and current surveillance schemes for foods are based on the assumption that all Listeria monocytogenes isolates are potentially pathogenic, resulting in costly recalls in food industry (Oevermann et al. 2010).
While listeriosis is greatly aided by early administration of antibiotics with rapid bactericidal activity against Listeria monocytogenes, research to improve food safety is directed to exploring novel technologies such as the use of bacteriophage for specific killing of bacteria.
Bacteriophages are viruses that infect bacteria. They are obligate intracellular parasites and lack their own metabolism. Phages are the natural enemies of bacteria. They are host-specific in that they infect specific bacterial species or even specific strains (Hagens and Loessner 2007). There are a few exceptions like Listeria bacteriophage A511, which can infect and kill bacteria within an entire genus. The extreme specificity of phages renders them ideal candidates for applications designed to increase food safety. Phages can be used for biocontrol of bacteria without interfering with the natural microflora.
Endolysins from Listeria bacteriophages are promising tools for detection and control of Listeria contamination and infection. These proteins have a modular organization, which is characterized by an N-terminal localized enzymatically active domain (EAD), which contributes lytic activity, and a C-terminal localized cell wall binding domain (CBD), which targets the lysin to its substrate.
It is an object of the present invention to provide a novel Listeria bacteriophage and novel endolysins against Listeria, which exhibit improved properties over known Listeria bacteriophages and known endolysins against Listeria. 